An electrostatic capacity type touch panel is a device for detecting a touch position by capturing a change of electrostatic capacity caused by approach of an electrically conductive body such as a finger of human. For example, such an electrostatic capacity type touch panel is used as a touch switch realizing a switching operation when a finger contacts with a predetermined portion of the panel.
Further, a display device with an electrostatic type touch panel function has been developed, which is a device wherein an electrostatic type touch panel is disposed on e.g. a front surface of a liquid crystal display device to integrate display and input functions.
For example, when portions to be detected are determined in advance, as shown in FIGS. 17(a) and 17(b), it is sufficient that transparent electrode patterns made of e.g. ITO (indium tin oxide) are disposed at such portions and wirings are made to the electrodes. FIGS. 17(a) and 17(b) are explanation views showing an arrangement example of transparent electrode patterns in an electrostatic capacity type touch panel. Here, FIG. 17(a) shows an arrangement example of transparent electrode patterns observed from a front side (a side to be touched) of a touch panel. Further, FIG. 17(b) is a cross-sectional view (A-A′ cross-sectional view) of the touch panel shown in FIG. 17(a). In the example shown in FIGS. 17(a) and 17(b), on a rear surface of a transparent substrate 91 (a surface opposite from a side to be touched), transparent electrodes and their lead wires are formed so as to corresponding to respective portions to be detected.
However, in order to detect an optional touch portion in terms of its x-y coordinate, it is necessary to arrange transparent electrode patterns in a matrix form in x-direction and y-direction, and to detect a touch position from their intersection points. Here, “arrange in a matrix form” means to arrange transparent electrode patterns forming columns in two directions independently so that columns of electrode patterns in one direction intersect columns of electrode patterns in the other direction.
As a method for forming an arrangement in such a matrix form, there is a method of preparing at least two transparent substrates each having a surface on which transparent electrode patterns arranged in one of the directions constituting the matrix form are formed, and laminating these transparent substrates on which such transparent electrode patterns are formed, via e.g. a resin to constitute a matrix form (hereinafter referred to as a first method).
FIGS. 18(a) and 18(b) are explanation views showing an arrangement example of a case of arranging transparent electrode patterns in a matrix form by using the first method. Here, FIG. 18(a) shows an arrangement example of transparent electrode patterns observed from the front side of a touch panel, and FIG. 18(b) is a cross-sectional view (A-A′ cross-sectional view) of the touch panel shown in FIG. 18(a). In the example shown in FIGS. 18(a) and 18(b), four columns of transparent electrode patterns 921 are formed on one surface of the transparent substrate 911 so as to correspond to respective X coordinates, and six columns of transparent electrode patterns 922 are formed on one surface of another transparent substrate 912 so as to correspond to respective Y coordinates, and these two transparent substrates 911 and 912 are bonded by using an adhesive agent 93 such as a resin to constitute transparent electrode patterns arranged in a matrix form.
Further, as another method, there is a method of forming transparent electrode patterns arranged in respective directions on surfaces of front side and rear side of a single transparent substrate, to arrange the transparent electrode patterns in a matrix form (hereinafter referred to as a second method).
FIGS. 19(a) and 19(b) are explanation views showing an arrangement example of arranging transparent electrode patterns in a matrix form by using the second method. Here, FIG. 19(a) shows an arrangement example of transparent electrode patterns observed from the front side of a touch panel, and FIG. 19(b) is a cross-sectional view (A-A′ cross-sectional view) of the touch panel shown in FIG. 19(a). In the example shown in FIGS. 19(a) and 19(b), four columns of transparent electrode patterns 921 are formed on a surface of the front side of a transparent substrate 91 so as to correspond to respective X coordinates, and six columns of transparent electrode patterns 922 are formed on a surface of the rear side of the transparent substrate 91 so as to correspond to respective Y coordinates, to arrange the transparent electrode patterns in a matrix form.
Further, an example of electrostatic capacity type touch panel wherein transparent electrode patterns are arranged in a matrix form, is described in, for example, Patent Document 1.